The spark plugs were the old ones... Maybe they were worn? The new ones I bought haven't been on yet. I honesty have no clue about anything too technical. I wish I did. Many of your (and everyones) comments while being obviously helpful I just can't understand. I will show them to my mechanic friends though, so they are useful! I'm just sorry I can't tell you all more.
Condenser... I know I sound stupid but what is this? Is it a big job to fix? Ahh I wish I was mechanicly minded!
No very simple. One small screw and two wires to unclip then clip back on if I remember rightly. If you put a photo of your dizzy on then it can be pointed out to you.
You will learn, you have to. If you don't understand, ask. Condensor is the small battery shaped thing with a green wire screwed onto the side of your distributor. It's there to stop radio interference only but will stop your engine running if broken. Common fault, just a few quid (literally) and a screwdriver.
I am away to take photos of it all now as the storm outside has lessened. Please keep looking... They will be up asap!
Is it single carb 1600? Maybe the leads /condenser/points werent right, then your mate over adjusted carb to compensate, now its flooding and not starting. Put carb back to base settings, check diz cap and leads then try again
No worries....hope you manage to get it sorted. the condenser acts like a capacitor (or a tiny battery) to store +ve charge, until your points open...on the side of the dizzy...you may not have one if an electronic module has been fitted if after changing the rotor/cap the bus ran well but then dropped, but you're still getting a healthy spark and fuel is being pumped out of the fuel line, it sounds to me like the fuel isn't being delivered turn the engine over for about 10 seconds, take out a plug and see if it is wet and smells of fuel
But they would deteriorate over thousands of miles and all 4 would not give up the ghost at the same moment. Back firing (decelerating)will be a hole the exhaust somewhere, when you get it running use a length of garden hose as a stethoscope to locate leaks.
Also...if you have the original carb fitted, there is an autochoke mechanism which, if faulty, can be responsible for starting issues...check that the wire between terminal 15 on the coil and the autochoke is actually connected...this is tucked behind the carb and easily disturbed similarly, check that any small hoses going to the carb are connected and/or plugged